1. Field of the Invention
The present invention relates to data output apparatus for recording or displaying data such as character, symbol, figure etc. data and also to a character pattern generator for rotating a dot pattern expressed as a matrix at the time of recording or displaying the data.
2. Description of the Prior Art
Various types of output apparatus for page data have been proposed and also are under development which use an electrostatic recording system employing, for example, a laser beam or optical fiber, ink jet recording system or CRT display system.
In such type of apparatus, some page data are put into the apparatus in a constant and successive line by line fashion from input means such as magnetic tape. The input data are stored in memory and the stored data are sequentially taken up line by line to produce character codes continuously and sequentially for every line relative to the sweeping direction of scanning means such as laser beam. In response to the character code a necessary character signal is generated to record the character on a recording medium such as recording paper.
Therefore, with the known recording apparatus, recording of literal data is performed line by line in the direction intersecting at a right angle the moving direction of recording medium P (secondary scan direction 13) as shown in FIG. 1. This recording mode is hereinafter referred to as vertical mode.
However, sometimes it is desirable to make the literal data recorded on a recording medium line by line in the direction parallel to the moving direction of the recording medium as shown in FIG. 2. This recording mode is hereinafter referred to as horizontal mode. Of course there may occur such case in which it is wished to convert the horizontal mode to the vertical mode.
All the known recording apparatus lack ability to perform such conversion of data arrangement with respect to a page line, which has given the user much inconvenience. Another disadvantage involved in such known recording apparatus is the inability to carry out recording at high speed and continuously from one page to the next page. When the memory has only one page capacity, it is impossible to start recording of one page immediately after completion of recording a prior page.
To change over the direction of page data arrangement from one to another mode relative to the moving direction of recording medium P, the dot pattern of character obtained by the characters generator must be displaced by a certain rotation angle. The method hitherto used to rotate the dot pattern is to conduct a matrix operation with software. However, this known method involves many processing steps and therefore it is impossible to attain a high speed rotation of the dot pattern.
In most apparatus for recording or displaying characters, the dot pattern of characters usually has directivity (vertical mode or horizontal mode). Therefore, for such character display apparatus capable of working in both of a vertical mode and a horizontal mode it is required to provide the apparatus with two kinds of character dot patterns, one for the vertical mode and the other for the horizontal mode. This means that the capacity of memory must be doubled. Therefore, the number of memories necessary for such a character display system capable of working in both modes is inevitably increased which is undesirable in view of economy.